Burj Dubai, the world's tallest building since July, has also become the tallest free-standing structure on earth, reaching 1,822 feet, the developers said.

The Dubai Tower's final height is a closely guarded secret, but completion of the concrete, glass and steel structure is expected by the end of 2008. The building's relentless climb is one example of Dubai's stratospheric rise from a sleepy desert town on the Persian Gulf to one of the principal business centers in the Middle East.

The Burj Dubai surpassed Canada's Toronto-based CN Tower on Thursday, which at 1,822 feet, had been the world's tallest free-standing structure since 1976, the developers said in a press release.

In July, the Dubai Tower, as it is known in English, moved past Taiwan's 1,667-foot Taipei 101, the highest skyscraper in the world since 2004.

"The Burj Dubai is setting new world records in the construction of super-tall buildings," said Mohmmad Ali al-Abbar, chairman of Burj's state-owned developer, Emaar Properties.

"This architectural and construction masterpiece is truly an inspirational human achievement that celebrates the can-do mind-set of Dubai," al-Abbar said to local media Thursday.

By the end of 2008, the developers say, the Burj will fulfill all four criteria for the tallest building, listed by the Chicago-based Council on Tall Buildings and Urban Habitat. The criteria include: the height of the structural top, the highest occupied floor, the top of the roof, and the tip of the spire, pinnacle, antenna, mast or flag pole.